Skirmish 40K (ITEN, Deathsquads40K rules as well)
Necromunda
Mordheim or conceivably skirmish WHFB (never cared for the full-on game)
Battle Fleet Gothic
Aeronautica Imperialis (I would buy the book and a squadron if I could find people to play with)
Dark Future (I actually have the game, never played it)
Epic 40K (Titans, mostly, I'd field a full team of War Hounds or Eldar light titans/dreads)
Space Hulk
LOTR